The stage prior to an aircraft landing is one of the most difficult stages of a flight plan and it requires sustained attention on the part of the aircraft pilot since it is necessary to keep track of a very large number of parameters, some of which are capable of varying rapidly. The aircraft must be maintained in a vertical plane containing the axis of the runway, regardless of wind speed and force. The pilot takes account of the image of the landing runway as seen visually, which image changes quickly during the approach stage and may be incomplete in misty weather.
The object of the present invention is to provide a method of guiding an aircraft during the visual approach stage giving the pilot an immediate visual indication that the aircraft is in the vertical plane containing the axis of the runway or if the aircraft is to the left or right of this plane.